For more than a year, Donald Trump and his associates have pushed back against allegations that his campaign colluded with the Russian government, which the president has called a “hoax” and a “witch hunt” orchestrated by Clintonworld. But a series of e-mails exchanged between the president’s son, Donald Trump Jr., and Rob Goldstone, a publicist and former British tabloid journalist linked to the Trump family through the Miss Universe pageant, suggests that the eldest Trump son not only sought compromising information on Hillary Clinton from a Kremlin-backed lawyer but was aware since at least June 2016 that the Russian government was working to help elect his father.

Just weeks after Trump clinched the Republican nomination, Trump Jr. received an e-mail from Goldstone informing him that one of his family’s former Russian business partners had received “official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father.” The e-mail chain, which began June 3, was also addressed to the president’s son-in-law and senior adviser, Jared Kushner, and then-campaign chairman Paul Manafort. “This is obviously very high level and sensitive information but is part of Russia and its government’s support for Mr. Trump.”

Trump Jr. responded, “if it’s what you say I love it especially later in the summer.” In a series of follow-up e-mails, he agreed to meet with the “Russian government attorney”—presumably Natalia Veselnitskaya, who later met with Trump Jr., Kushner, and Manafort at Trump Tower on June 9.

On July 22, WikiLeaks published some 20,000 Democratic National Committee e-mails, which are believed by U.S. intelligence agencies to have been stolen by hackers working for the Russian government.

The e-mails between Trump Jr. and Goldstone are the first concrete evidence that the Trump campaign was aware of Russian government effort to help elect Donald Trump—months before the Obama administration made the Russian campaign known, and long before Trump himself acknowledged Russian interference. “The new joke in town is that Russia leaked the disastrous DNC e-mails, which should never have been written (stupid), because Putin likes me,” Trump tweeted on July 25. The day before, Donald Trump Jr. had gone on CNN to decry the Clinton campaign’s claims that the Russians were helping Trump as “disgusting” and “phony.”

The president’s son released the e-mail exchange Tuesday after learning that The New York Times was about to publish a story containing parts of his conversation with Goldstone, which the paper published minutes later. The acknowledgement that he was aware of Kremlin efforts to help his father become president, and his eagerness to meet with a Russian intermediary to solicit the promised information, follows a series of incremental reports from the Times, to which Trump Jr. has responded with ever-shifting explanations. At first, Trump Jr. cast the rendezvous as a “short introductory meeting” in which the group discussed the Magnitsky Act—a retaliatory measure the U.S. leveled against Moscow, blacklisting suspected human-rights abusers. The following day, when the Times reported that the Trump campaign had been promised damaging information about clinton, Trump Jr. changed his story, explaining, essentially, that while Veselnitskaya had promised dirt, she didn’t deliver. “The woman stated that she had information that individuals connected to Russia were funding the Democratic National Committee and supporting Mrs. Clinton. Her statements were vague, ambiguous, and made no sense. No details or supporting information was provided or even offered. It quickly became clear that she had no meaningful information.”

On Monday, Trump Jr. hired New York-based lawyer Alan Futerfas, who has defended members of several major mob families. Collusion between Russia and members of the Trump campaign is one of several allegations being investigated by the F.B.I., under special counsel Robert Mueller, as well as by parallel inquiries by the intelligence committees in the House and Senate. Trump Jr. has said he would be “happy to work with the committee to pass on what I know,” in reference to the Senate panel.

In a statement Tuesday, Trump Jr. said that he believed that the information Veselnitskaya supposedly had was just opposition research. “The woman, as she has said publicly, was not a government official. And, as we have said, she had no information to provide and wanted to talk about the adoption policy and the Magnitsky Act,” he wrote. “To put this in context, this occurred before the current Russian fever was in vogue. As Rob Goldstone said just today in the press, the entire meeting was the ‘most inane nonsense I ever heard. And I was actually agitated by it.’”

In an interview with NBC News, part of which was published on Tuesday, Veselnitskaya denied that she ever had, or sought to share, compromising information about Clinton with the Trump camp. “I never had any damaging or sensitive information about Hillary Clinton. It was never my intention to have that,” she said. When asked why her version of events contradicted Trump Jr.'s the Russian lawyer responded, “It is quite possible that maybe they were longing for such an information. They wanted it so badly that they could only hear the thought that they wanted.”